========================================================================== Ubuntu Security Notice USN-8388-2 June 22, 2026
linux-intel-iotg-5.15, linux-lowlatency, linux-lowlatency-hwe-5.15
vulnerabilities
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS
Summary:
Several security issues were fixed in the Linux kernel.
Software Description:
- linux-lowlatency: Linux low latency kernel
- linux-intel-iotg-5.15: Linux kernel for Intel IoT platforms
- linux-lowlatency-hwe-5.15: Linux low latency kernel
Details:
It was discovered that the Linux kernel did not properly handle shared page
fragments during socket buffer operations, collectively known as Dirty
Frag. A logic flaw existed in the XFRM ESP-in-TCP subsystem and in the
RxRPC networking subsystem when processing paged fragments. A local
attacker could use this to escalate privileges, or possibly escape a
container. (CVE-2026-43284, CVE-2026-43500)
It was discovered that a logic flaw existed in the XFRM ESP-in-TCP
subsystem in the Linux kernel when handling socket buffer fragments. This
flaw is known as Fragnesia. A local attacker could use this to escalate
privileges, or possibly escape a container. (CVE-2026-43503,
CVE-2026-46300)
Qualys discovered that a race condition existed in the ptrace subsystem of
the Linux kernel when privileged processes are exiting. An unprivileged
local attacker could use this issue to expose sensitive information.
(CVE-2026-46333)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- RDS protocol;
(CVE-2026-43494)
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 22.04 LTS
linux-image-5.15.0-181-lowlatency 5.15.0-181.191
linux-image-5.15.0-181-lowlatency-64k 5.15.0-181.191
linux-image-lowlatency 5.15.0.181.152
linux-image-lowlatency-5.15 5.15.0.181.152
linux-image-lowlatency-64k 5.15.0.181.152
linux-image-lowlatency-64k-5.15 5.15.0.181.152
Ubuntu 20.04 LTS
linux-image-5.15.0-1104-intel-iotg 5.15.0-1104.110~20.04.1
Available with Ubuntu Pro
linux-image-5.15.0-181-lowlatency 5.15.0-181.191~20.04.1
Available with Ubuntu Pro
linux-image-5.15.0-181-lowlatency-64k 5.15.0-181.191~20.04.1
Available with Ubuntu Pro
linux-image-intel 5.15.0.1104.110~20.04.1
Available with Ubuntu Pro
linux-image-intel-iotg 5.15.0.1104.110~20.04.1
Available with Ubuntu Pro
linux-image-intel-iotg-5.15 5.15.0.1104.110~20.04.1
Available with Ubuntu Pro
linux-image-lowlatency-5.15 5.15.0.181.191~20.04.1
Available with Ubuntu Pro
linux-image-lowlatency-64k-5.15 5.15.0.181.191~20.04.1
Available with Ubuntu Pro
linux-image-lowlatency-64k-hwe-20.04 5.15.0.181.191~20.04.1
Available with Ubuntu Pro
linux-image-lowlatency-hwe-20.04 5.15.0.181.191~20.04.1
Available with Ubuntu Pro
After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.
References:
https://ubuntu.com/security/notices/USN-8388-2
https://ubuntu.com/security/notices/USN-8388-1
CVE-2026-43284, CVE-2026-43494, CVE-2026-43500, CVE-2026-43503,
CVE-2026-46300, CVE-2026-46333
Package Information:
https://launchpad.net/ubuntu/+source/linux-lowlatency/5.15.0-181.191
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